Researchers: 91.7% of 376 former NFL players in study had CTE

Head injuries can lead to CTE in football players, but the condition cannot be diagnosed until after death, researchers say. File Photo by Archie Carpenter/UPI
1 of 4 | Head injuries can lead to CTE in football players, but the condition cannot be diagnosed until after death, researchers say. File Photo by Archie Carpenter/UPI | License Photo

Feb. 6 (UPI) -- Researchers at Boston University said they have identified chronic traumatic encephalopathy in the brains of more than 91% of former NFL players involved in an ongoing study of the delayed neurodegenerative disorder.

Scientists at Boston University's Chronic Traumatic Encephalopathy Center confirmed in a news release Monday that they identified CTE in 345 out of 376 players in the ongoing study or 91.7% of participants.


A CTE diagnosis cannot be made on a living person and must be conducted after death. Athletes, especially those in high-contact sports like hockey or football, must enroll in the study ahead of time, agreeing to donate their brains after they die.

Five clinical studies are looking at CTE, and February is CTE Awareness Month, researchers said.

A Boston University study in 2018 that looked at the brains of otherwise healthy people found only one out of 164 people had the condition. The lone positive diagnosis came in from a former college football player.


Monday's research included Super Bowl winner Ed Lothamer, a former member of the Kansas City Chiefs, and former Philadelphia Eagles quarterback Rick Arrington. The two teams play each other in Super Bowl LVII in Arizona on Sunday.

Lothamer won an NFL championship in 1970 when the Chiefs beat the Minnesota Vikings in New Orleans during Super Bowl IV.

CTE begins through abnormal accumulation of tau proteins in the frontal lobes of the brain. Those proteins then grow and spread as the diseases progresses through three subsequent stages. As that happens, a patient could experience a shrinking brain, which can be linked to dementia.

Cognitive symptoms like memory loss or and problems or multitasking and problem-solving can appear earlier on. A person also may suffer from severe mood swings and other behavioral issues.

In 2012, former NFL player Junior Seau died from a self-inflicted gunshot wound at the age of 43, two years after retiring from the game. The former linebacker was selected to 12 NFL Pro Bowls and was named the UPI Defensive Player of the Year in 1992.


After his death, researchers with the National Institutes for Health diagnosed Seau's brain with CTE.

"I miss my hero dearly," quarterback Arrington's daughter, Jill, a former sideline reporter with several networks, said in November during the Concussion Legacy Gala.

"It pains me to know his life was cut short by the sport he loved most. As a brain donor, part of his legacy is in this research, and I want all former football players to know how important it is to contribute and sign-up for studies so Boston University CTE Center researchers and their collaborators around the world can learn how to treat, and one day cure, the disease that devastated our family."

Rick Arrington was diagnosed with stage 4 CTE after he died at age 74 in 2021.

People who have suffered repeated blows to the head or multiple concussions may run a higher risk of developing CTE.

"While the most tragic outcomes in individuals with CTE grab headlines, we want to remind people at risk for CTE that those experiences are in the minority," Boston University Center Director Dr. Ann McKee said in a statement Monday.

"Your symptoms, whether or not they are related to CTE, likely can be treated, and you should seek medical care. Our clinical team has had success treating former football players with mid-life mental health and other symptoms."


Boston University researchers cautioned that the findings released Monday do not necessarily equate to a comparable rate of CTE among current NFL players.

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